updating the readme file

Author: akumar91

README.md

@@ -35,4 +35,4 @@ Pre-requisites:
 - Perl 5.20.2 or higher
 
 Use the following commands to run the perl samples.
-- `perl create_policy_with_defaults.pl -nbmaster localhost -username testuser -password testpass -domainName test -domainType vx`
+- `perl create_policy_with_defaults.pl -nbmaster <masterServer> -username <username> -password <password> -domainName <domainName> -domainType <domainType>`